26
2(sinx+cosx)+(sinx+cosx)²=0
(sinx+cosx)(2+sinx+cosx)=0
sinx+cosx=0/cosx
tgx+1=0
tgx=-1
x=-π/4+πk,k∈z
2+sinxcosx=0
2cos²(x/2)+2sin²(x/2)+2sin(x/2)cos(x/2)+cos²(x/2)-sin²(x/2)=0
sin²(x/2)+2sin(x/2)cos(x/2)+3cos²(x/2)=0/cos²(x/2)
tg²(x/2)+2tg(x/2)+3=0
tg(x/2)=a
a²+2a+3=0
D=4-12=-8<0 нет корней<br>Ответ D
27
(∛x+∛y)(x-y)(x+y)/[∛x²(x+y)-∛y²(x+y)]-(∛(xy)+∛y²)=
=(∛x+∛y)(x-y)(x+y)/(x+y)/(∛x²-∛y²)-(∛(xy)+∛y²)=
=(∛x+∛y)(x-y)/(∛x+∛y)(∛x-∛y)-(∛(xy)+∛y²)=
=(x-y)/(∛x-∛y)-(∛(xy)+∛y²)=(∛x-∛y)(∛x²+∛(xy)+∛y²)/(∛x-∛y)-(∛(xy)+∛y²)=
=∛x²+∛(xy)+∛y²-∛(xy)-∛y²)∛x²
x=64 ∛64²=4²=16
Ответ В